1. Field of the Invention
This invention relates to the field of computer systems and, more particularly, to reboot operations in computer systems.
2. Description of the Related Art
As computer systems become increasingly important to modern business and industry, maintaining key systems at a high level of availability becomes increasingly critical. For example, one definition of so-called “high-availability” systems is a system which is fully functional 99.999% of the time, or a system which is unavailable less than ten minutes each year. Accordingly, many maintenance and upgrade procedures that would traditionally be verified by restarting or “rebooting” a computer system are now completed without a reboot, thereby avoiding any downtime which would decrease system availability.
Dispensing with a verification reboot of the system, subsequent to a system configuration change, means that modifications to the reboot are untested. Furthermore, multiple changes which affect the reboot process or the post-reboot configuration of a given server computer after a reboot may be made in the months or years between actual reboots of the server. For example, a system administrator may install software upgrades to the system network or upgrades to system before an intentional or unintentional system restart occurs.
An error made during such changes may place the system in an undesirable, unstable or non-functional state after a reboot. However, such a configuration error may be difficult to diagnose, since no clear indication may exist as to which modification or combination of modifications caused the error. Accordingly, system administrators may face a choice between high availability or frequent reboots for system verification purposes.